The Cisco 16-Port OC-3c/STM-1 ATM Switch Service Module is a line card for use in the Cisco MGX 8800/8900 Series multiservice Cisco MGX Switches in combination with the Cisco MGX 8800/8900 Series PXM-45 Processor Switch Module and the Cisco MGX 8950 XM-60 Switching Module (the latter for use on the Cisco MGX 8950 only). This ATM switch service module has 16 physical 155-Mbps interfaces that can be used to deliver high-density OC-3c or STM-1 trunking and User-Network Interface (UNI).